SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5f21a9bf50fb31ceda720706b4939b944d6e9fdcb185b1e3aaf6ca753486b87f' 
  AND token = '8pE3ARj0FD0sGovNqfo/nJWKqcYSARGTn3jz4RZjWMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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