SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'caab9535bd43af86c45ec3a46dd39a5ff1a5f5daa42acb1ac407869d32bc5455' 
  AND token = 'a8q/j+RCzTqwbrz1IMP9sK1X4sG+o/MtPUYUpfMTy1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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