SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e57ad9286b9d7b21bbf37bfc5a2fbd99b2a1867b708b71605d6fb1440e171ed6' 
  AND token = 'rEOlyszEYGKHock+2s/anL11h7ghUDA1SELAnXHILok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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