SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7dacf241050d470838a5d87412233d1352cbe1f28df558618e198a351707430' 
  AND token = 'NNEZUofU7IW3CNXJGCZ4NERd0xKnXEvflQ+wPCF2UzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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