SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '027c3ee6b23145b0cb574fe789e15177b3472d81aad151ec8de703a0e8e14537' 
  AND token = 'PjaVcMdWTrtLpGRBQGwMz1yRYoxhrxkoNBVe5frK1Ag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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