SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c663f0cdb61571f920baf74019008ce68f85f303707a1324a76a113ae386c0b9' 
  AND token = 'nAQBrJ57R2v30yQnFONGc1/cHWC1JVIYPAKdi9IlmSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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