SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5414f5b27ca325f0471cdb95bfaf63b5d2990f4d4520009c4e15c5812140377e' 
  AND token = 'AwufdBcb0DVfp+kiXEvQPziuFuQhYSt5oXreJzdLn9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}