SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ea08b32e1bc9becb586faee00c9dd4b33e737a1670b29bd454f883d7bd5e799' 
  AND token = 'OaiKx3083YcMdk7flasVPXzSHFIzv7dBcb8VTvEkTls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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