SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '49036c3591aa64e57278515b34fbed266808944717b0b1c575e51e95898a98d5' 
  AND token = 'PF7BD2YQK+zmvUyxB0KsXJr1jWMisYQPlnB0w3M5RWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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