SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df071ae08d3cf0bb1ae3903b5ee7ef1e1971d6a911b390b9ec1326262e053421' 
  AND token = 'TAPQifLybCii3VeW+jYyp/Iv5n+5El6a6y+0wDxkyfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}