SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f847d4d842e1ebca736f03a1c8c7d57f2b95306d994d5d85c09e96873659f0df' 
  AND token = 'E/vA5BwCBBcuTNbwgoDCTDD86FMB433tQ0cmGMIZyV0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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