SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e87a5bdb727b3a7df4b59111bf5e79bdfc9d0ef555461d3be2d3cf40adebb492' 
  AND token = 'rIK5aVGusjE1MoPAZXljrrpzxkPouJLtPOPevUGvd1A=' 
  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"
    }
  }
}