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SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a75e0cd5241728a3b5b2edc9561daa3ea1b80ac716d13466fb9a0f67e3f43fc9' 
  AND token = 'FFMLj2YWMUres6o4Dsonq2Ng7vIXt8BUfPaAemc5VhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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