SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '850c871e69f8c14ac71370a1f3f5f2fe5469844dade36ec8147b101b6b2a04c5' 
  AND token = 'JyDYMbOthtPQy2iSbn2XP18jvkKwSWYjMHdEdfuuLuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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