SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '288da71e9b55a08d5c7b995106f0c93cacd0a27b733338a220af4aab5240db85' 
  AND token = '1Ej9Lcp4vKcBksFFJkzm3dt3R3WgwlV7A0Vi+Wxzmn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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