SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3785d95c1bb189b1a86b3d347a7341611aececeee871fd8497cc9a6db25e680a' 
  AND token = 'Ck2Tu+kpRmGbpViTQsLRpIjZaMgvg8pb9MGm3/83ALc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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