SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e485cb6e1f568bc5ca365824b76298192a96bcee5122efdfb54a71383dd056ca' 
  AND token = 'da8dCmPWGBEnfV1t2cT3Vn9gmQ23QMbiwgeFijKSl0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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