SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9ce3688f38b7d04d6a5e273ba8ec12ba2419e5c8797596704a4f6a24c061127' 
  AND token = 'i4ELG7E+6hhrzlwQusP/UvURIcmNXpfETOf+D37JgcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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