SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '071a52d8d523a6ad53c563c1bf9fbf743d8b29ff446dc39cdcd7d4bea761420a' 
  AND token = 'y5e3I9XZ15cXpHWKHqNEwwbrnT9p1qH781s2Hi+eUI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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