SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd19a78f206f00dbc1d1c6b04534dac64de418533cc15c9066d4f448c34f23f64' 
  AND token = 'tmELGNR8PemsEFsYN4uIsLSNoMNe/MuyzY4E7hcHqJY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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