SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '852d08f20398f6bd7aba268f7a972b29d85199d5a62383957381f66cfc9185a1' 
  AND token = 'BBIVpK/y+F2IEHvibgxNmpbOfFAC4g83sXIL8/zmS4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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