SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '637b02f78cf5843d6e5c3875baabd18d9727d4fd8f711e06c27d0b83803284af' 
  AND token = 'S4VPKw0ZrJff/eWPyB+uEDxxBrF/xWFwFGdz8ThcQHA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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