SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6e12b1f79719ade1e1631116dc87d4a31fae672efd5890a6eda17310b80c8692' 
  AND token = '5OZ24wCeCklV/Q3xkA88VXSQ2BvCgEhmXPNSKXMbaKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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